Have you ever been driving along and then noticed that even when you put the pedal to the metal, the tachometer shoots up and the rpms power toward the redline, but your car doesn’t get that forward surge of power that you were expecting? If you’ve ever experienced this, what you’ve just witnessed was the clutch slipping.
In today’s blog, we’re exploring the reasons that your clutch will slip, and what you can do about it when it happens. First of all, let’s be clear on what your car’s clutch actually does.
What Does a Clutch Do?
Put simply, the clutch is the component that allows rotational power from the engine to be transferred to the wheel of a vehicle. It is a connecting part between various rotating shafts. When you engage the clutch, the connection between the wheel and the engine has to be temporarily severed to allow for the car to stop without needing to turn off the engine, and to allow smooth and proper gear shifting.
The clutch is made up of three main components, the clutch plate, pressure plate and the flywheel. Pressing down on the clutch pedal releases the springs that ordinarily hold the pressure plate against the clutch plate and the clutch plate against the flywheel. Separation of the clutch plate and flywheel is essential when changing gears or coming to a stop.
What Does Clutch Slipping Mean?
Clutch slipping is a problem whereby the clutch engages and disengages with no power being delivered to the wheels of the car as it should. That transfer of rotational power that we mentioned above it not occurring. If you drive a vehicle with a manual transmission, then it’s something that could easily happen to you sooner or later.
A good mechanic should be able to detect problems in the clutch when they inspect it. A clutch needs a full and proper inspection every 60,000 to 100,000 miles, but at least a cursory inspection is likely at your annual service, too. There are several known causes of clutch slippage, which we will explore below.
What Causes a Clutch to Slip?
Like most components within your car, the chief reason behind the problem is wear and tear. If you have a manual car and you drive a lot, then the clutch bears a lot of the brunt of wear and tear, as do your tires and brakes. The wear and tear can manifest as a clutch slipping under 4 main circumstances:
- Warping in the flywheel
- Worn pressure plate
- Leaking cylinder
- Faults in the clutch plate
- Worn throwout bearing
Warping in the Flywheel
Your clutch’s flywheel gives mass, inertia and rotation that helps to keep the engine running. It balances the crankshaft and is the key component in ensuring a smooth transfer of power from engine to transmission. It’s a component in constant motion and therefore also experiences a great deal of friction. The heat from this friction can cause the flywheel to become warped.
Worn Pressure Plate
Bolted to the flywheel is the all-important pressure plate. The same heat that warps your flywheel also affects the pressure plate, reducing its capacity to apply the pressure needed for the power flow between engine and transmission.
Leaking Cylinder
If you’re driving a newer vehicle, then it’ll have a hydraulic clutch with both slave and master cylinders. The seals on these cylinders are exposed to great pressure and temperature shifts, causing them to leak and crack.
Faults in the Clutch Plate
The clutch plate is coated on both sides with a similar material that you’ll find on a brake pad. It helps the engagement between it and the flywheel to be smoother. These surfaces can wear down and warp, which ultimately can cause the clutch to slip.
Symptoms of a Clutch Slipping
If you’re not a mechanic, you might worry about knowing whether your clutch is really slipping or not. There are fortunately several symptoms for which you can look and get an idea if there really is a problem or not.
First, listen for unusual noises when pressing on the clutch. As you likely know, groaning, grinding, squeaking and similar noises are never a good sign on your car. If you hear them when you’re pressing on the clutch, then consider getting it checked.
Next, are you having any trouble changing gears? The clutch is supposed to make gear shifts easier, so if you’re having trouble making successful up or down shifts, then a slipping and faulty clutch is likely the cause.
Third, you’re revving but not accelerating. As we touched on the blog introduction, a common sign of clutch slipping is when you see the revs on the tachometer shoot up, but the car doesn’t surge forward in acceleration.
Finally, do you sense that the clutch feels spongy or that it’s sticking? The clutch pedal action should be smooth and easy. If the pedal feels “off” for some reason, you’ll likely detect it because it’s a pedal you use all the time. You may also feel a vibration when you apply the clutch.
How to Test a Clutch Slipping
The best way to test if you clutch is slipping is to try the sharp acceleration technique we mentioned above. Shift your car into a slightly lower gear; third gear works well. Once you’re safely in third, put your foot down on the gas and give it some real oomph.
If you see the tachometer shoot up, but the car barely accelerates, then that’s the most “classic” sign of a slipping clutch. It’s a simple test that you can do almost any time on the road. Just be careful not to exceed local speed limits as you test.
How Long Can I Drive With a Slipping Clutch?
If you’ve just noticed that your clutch has started slipping, then you needn’t panic. This isn’t one of those faults that should send you running in urgency to your local mechanic. Technically, you could drive for hours, days or even weeks on a slipping clutch, but the thing is, you definitely should not.
When minor faults start in any part of your car, you should get them seen to at the earliest possible opportunity, even those that don’t appear urgent. Any small mechanical problem in a car starts off that way and would be easy and cheap to fix, but sooner or later it turns into a much more complex and expensive problem unless you see to it.
What Should I Do If My Clutch is Slipping?
If your clutch is slipping, you should first take extra care while you’re driving. Lower your overall speed somewhat, and drive carefully until you can have a mechanic look at the clutch and fix it up. What you absolutely should not do is procrastinate about the problem, for the reasons we just described in the section above.
How to Fix a Slipping Clutch
Hopefully the damage isn’t such that you will need an entirely new clutch, but it is a likely outcome. If it’s one of the components that is behind the problem, then they may be able to be repaired or replaced individually. Here are all the possible methods that can be used to repair a slipping clutch and stop it from happening:
- Clutch replacement. How complex a clutch replacement job is will depend on whether your car is a FWD or RWD drivetrain. On a FWD, it’s a much harder job because it requires the engine to be removed and hoisted up and the transaxle dropped down. That’s more equipment and labor, which will push up the cost.
The following steps are all part of a clutch replacement. If the problem lies in just one of these components, then they could be carried out individually:
- Resurfacing or replacing the flywheel. The flywheel can be resurfaced if it needs, but if there is oil contamination, grooves from warping or heat discoloration, then it will have to be replaced.
- Replacing the throwout bearing. This step will likely be needed at any level of clutch repair because any new components brought to your clutch will need a fresh bearing.
- Check the pilot bushing. This bushing is located near the crankshaft and if your vehicle with a slipping clutch is also one with a high mileage, then replacing the bushing could be a necessary step as part of fixing the clutch.
Cost of Fixing a Slipping Clutch
The difficult news is that repairing a clutch can cost anywhere from $500 to $2500. If you need an entirely new clutch on a FWD vehicle, then you are looking at the higher end of that spectrum. If it’s minor damage on a RWD vehicle, then expect it to be somewhat closer to the lower end. Fixing or replacing individual components will keep the price lower, but there’s a good chance that the circumstances will warrant a full replacement.
The best way to avoid that sudden huge bill is to keep your clutch well maintained and in good order. Small repair and maintenance costs in the short term will always work out cheaper in the long term than facing a full and premature clutch replacement.
How Long Do Clutches Last?
When properly maintained, a clutch should last up to 80,000 miles or so. There’s nothing you can do to prevent wear and tear on the clutch. It’s an inevitable part of its function. Having said that, you can minimize the damage by driving sensible, avoiding bad habits like riding the clutch, and generally not putting too much strain on it. On top of that, and as we’ve mentioned above, you should keep your clutch well serviced and maintained.
